[pbs-devel] [PATCH proxmox-backup 0/7] add, persist and check key fingerprint

[Dietmar Maurer]

> On 11/18/2020 6:27 AM Dietmar Maurer <dietmar at proxmox.com> wrote:
> 
>  
> Do we really need/want a 256bit long fingerprint?
> 
> I thought 64bit (or maybe 32bit) would be large enough?
> If not, why does it have to be that large?

some quick math:

max keys a user generate in his live: 1024 (2¹⁰)

so the likelihood of a 32bit fingerprint clash is 

W = 1/2^²²   (1/4Millions)

which is, unlikely, but possible.

But with 64bit it is extremely unlikely (1/2⁵⁴).